The invention is related to a clamping device for clamping a workpiece, in particular but not limited to a workpiece for constituting a catheter. The invention is also related to an installation comprising at least one of such a clamping device.
Catheters are constituted with tubes of little diameter. A part of the tube should be stiff as the catheter has to be pushed in a vein of a patient, and a terminal part should be more flexible to be directed to a direction or a location for exerting an action. Thus it is known assemble two parts of the catheter, but having the same or different diameters, or in different materials. The materials are in general a thermoplastic resin. The two parts are issued from the assembling of two workpieces in abutment by welding or bonding. As it is important that there is no knifing or aggressive protrusion on the outer surface of the catheter, the workpieces are to be well aligned during the assembling.
For that, it is known to use a clamping device to hold one of the workpieces, the clamping device comprising a mandrel having a central hole and a housing surrounding the mandrel. The device comprises means for compressing the mandrel. A workpiece in form of a tube is introduced in the central hole in a manner that when the mandrel is compressed, the inner diameter of the central hole is reduced and tight the part. An installation for assembling two workpieces comprises two clamping devices having mandrel with the same axis to align the two workpieces.
Although this device allows a good alignment and assembling, the device has not good performances. The parts before the assembling must be introduced in the mandrel by a translation movement in axial direction, which can be long and tricky. Furthermore, the deformation of the mandrel induces slipping between the mandrel and the part, and thus wearing of the mandrel. Thus the mandrel has to be changed frequently.